Continuously Tunable Optically Pumped High-Pressure DF Yields CO2

摘要

The possibility of operating a continuously tunable high pressure CO2 laser by exciting the gas optically with radiation from a pulsed DF laser is studied. The pumping radiation is absorbed by DF in a high pressure DF/CO2/He mixture, and subsequent vibrational energy transfer to the CO2nu3 mode provides the CO2 laser population inversion. Continuous tuning of the CO2 laser frequency between two CO2 line centers in the R branch at 10.26 microns is demonstrated at 12 atm laser gas pressure. The operational characteristics of the laser are studied for several gas mixtures at gas pressures up to 19 atm. For a 10 atm gas mixture containing 0.6% DF, 5% CO2 and 94.4% He the maximum CO2 laser output energy obtained with a two mirror CO2 laser resonator is approximately 6 mJ, corresponding to a total quantum efficiency of 20%. The slope quantum efficiency is then about 35%. A maximum output energy of 1 mJ is obtained in the frequency tuning experiments. A theoretical laser model is outlined, and the results of computer simulations based on this model are in reasonable agreement with the experimental results.